In-vivo introducible antenna for detection of rf tags

ABSTRACT

An interrogation and detection system for detection of surgical implements within a patient&#39;s body, the system including One or more RFID tags affixed to a surgical implement within the patient&#39;s body. Each RFID tag being configured to transmit a return signal when energized, and a remote signal generator configured to generate an energizing signal for the one or more RFID tags. The signal generator operably coupled to the in-vivo introducible antenna via a communication cable. The system further includes an in-vivo introducible antenna configured to be inserted through a trocar-cannula assembly into a surgical site within the patient&#39;s body. Wherein the tubular channel defines a shape having a dimension “D1”, such that the dimension “D1” of the tubular channel is less than the dimension “D2” of the in-vivo introducible antenna.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of and priority to U.S.Provisional Patent Application Ser. No. 63/002,487, filed on Mar. 31,2020, the entire content of which is incorporated by reference herein.

TECHNICAL FIELD

This disclosure relates generally to interrogation and detection systemsfor the detection of radio-frequency (RF) tags, and more particularly,to insertable antennae for use within surgical sites.

BACKGROUND

It is often useful or important to determine whether objects associatedwith a surgery are present in a patient's body before completion of thesurgery. Such objects may take a variety of forms. For example, theobjects may take the form of instruments, for instance scalpels,scissors, forceps, hemostats, and/or clamps. Also, for example, theobjects may take the form of related accessories and/or disposableobjects, for instance surgical sponges, gauzes, and/or pads. Failure tolocate an object before closing the patient may require additionalsurgery, and in some instances may have serious adverse medicalconsequences.

Some hospitals have instituted procedures which include checklists orrequiring multiple counts to be performed to track the use and return ofobjects during surgery. Such a manual approach is inefficient, requiringthe time of highly trained personnel, and is prone to error.

Another approach employs transponders and a wireless interrogation anddetection system. Such an approach employs wireless transponders (e.g.,RFID tags) which are attached to various objects used during surgery.The interrogation and detection system includes a transmitter that emitspulsed wideband wireless signals (e.g., radio or microwave frequency)and a detector for detecting wireless signals returned by thetransponders in response to the emitted pulsed wideband signals. Such anautomated system may advantageously increase accuracy while reducing theamount of time required of highly trained and highly compensatedpersonnel. Examples of such an approach are discussed in U.S. Pat. No.6,026,818, issued Feb. 22, 2000, and U.S. Patent Publication No. US2004/0250819, published Dec. 16, 2004.

Commercial implementation of such an automated system requires that theoverall system be cost competitive and highly accurate. In particular,false negatives must be avoided to ensure that objects are notmistakenly left in the patient. Direct interrogation of the surgicalsite, by transmitting a probing signal from within the open surgicalsite is a straightforward approach to reducing the effect of signalinterference due to external factors. However, the size of thetransmitting antenna limits the utility of this option. The minimallyinvasive approach to modern surgery discourages clinicians from cuttinglarge open wounds into the body of the patient. Instead of large cuts toaccess treatment sites within the body, small apertures provide accesspoints for surgical tools to be used internally. These apertures aregenerally too small to facilitate insertion of transmitting antennaeinto the treatment site for direct interrogation.

Furthermore, when trying to locate an RFID tagged item within thesurgical site it is important for the antenna transmitting the probingsignals and receiving the return signals to physically occupy as muchspace as possible, because larger antennae have a greater range ofdetection for return signals within the surgical site. Accordingly, itis desired to bypass external sources of signal interference by directinterrogation within the surgical site with a relatively large sizablyadjustable antenna capable of passing through the small aperturesgenerally employed in modern surgical practice.

SUMMARY

This disclosure relates to systems for detection of surgical objects anddevices used in body cavities during surgery, specifically antennae tobe inserted directly into a surgical site.

One aspect of the disclosure is directed to an interrogation anddetection system for detection of surgical implements within a patient'sbody. The interrogation and detection system includes one or more RFIDtags configured to transmit one or more return signals when energized,each RFID tag affixed to a surgical implement within the patient's body;a remote signal generator configured to generate an energizing signalfor the one or more RFID tags; and an in-vivo introducible antennaoperably coupled to the signal generator, the in-vivo introducibleantenna configured to receive the one or more return signals transmittedby the one or more RFID tags when in an expanded state. Wherein thein-vivo introducible antenna is configured to a collapsed state, smallerthan the expanded state, for insertion into the patient's body.

The system may further include a trocar-cannula assembly including atubular channel configured to facilitate passage of the in-vivointroducible antenna therethrough, wherein the in-vivo introducibleantenna defines a shape having a dimension “D2”; and wherein the tubularchannel defines a shape having a dimension “D1”, such that the dimension“D1” of the tubular channel is less than the dimension “D2” of thein-vivo introducible antenna.

The in-vivo introducible antenna may include a semi-rigid elongatedmember supporting a flexible loop configured to fold in on itself whenpassing through the tubular channel of the trocar-cannula assembly, andto unfold upon exiting the tubular channel of the trocar-cannulaassembly and entering the surgical site within the patient's body.

The flexible loop may be composed of a shape memory alloy configured toautomatically return to its initial shape in the absence of externalforces.

The initial shape of the flexible loop portion of the in-vivo antennamay be circular.

The flexible loop may be configured to be folded inward to form anelongated oval shape while being translated distally through the tubularchannel.

The flexible loop may be configured to be folded backwards to restalongside the semi-rigid elongated member while being translateddistally through the tubular channel.

The flexible loop may be configured to be folded along the axis of thesemi-rigid elongated member to form a crescent-shaped profile whilebeing translated proximally through the tubular channel.

The flexible loop may be tear drop-shaped.

The flexible loop may be larger in size than the tubular channel.

According to another aspect, a method for detecting one or more surgicalimplements within a patient's body is provided. The method includespushing an in-vivo introducible antenna distally through a channelhaving a dimension “D1” defined within a trocar-cannula assembly andinto a surgical site within the patient's body, wherein a portion of thein-vivo introducible antenna will automatically return to an originalshape having a dimension “D2”, such that the dimension “D1” of thetubular channel is less than the dimension “D2” of the in-vivointroducible antenna; generating an energizing signal configured tostimulate the one or more RFID tags into transmitting a return signal;transmitting the energizing signal directly into the surgical sitewithin the patient's body through the expanded portion of the in-vivointroducible antenna; scanning for any return signals from one or moreRFID tags affixed to each surgical implement placed within the patient'sbody before the surgery began; and alerting the clinician to thepresence of the one or more RFID tags affixed to each surgical implementupon detection of the one or more return signals.

The in-vivo introducible antenna may include of a semi-rigid elongatedmember supporting a flexible loop, where the flexible loop is theportion of the in-vivo introducible antenna configured to automaticallyunfold to occupy an expanded area.

The method may further include pulling the unfolded flexible loopportion of the in-vivo introducible antenna proximally through theaperture and channel of the trocar-cannula assembly such that theunfolded flexible loop is compressed by the channel and collapses in onitself.

The compression of the flexible loop portion may facilitate completewithdrawal of the in-vivo introducible antenna from the trocar-cannulaassembly.

The flexible loop portion may be circular in shape and configured tofold along an axis of the semi-rigid elongated member to form acrescent-shaped profile while being pulled proximally through thechannel of the trocar-cannula assembly.

According to yet another aspect, a resizable in-vivo introducibleantenna for insertion into a surgical site and detection of RFID taggedsurgical implements within a patient's body is provided. The Antennaincludes a semi-rigid elongated member configured to be translatedthrough a tubular channel, wherein the tubular channel defines a shapehaving a dimension “D1”; and a flexible loop operably coupled to thesemi-rigid member, wherein the flexible loop defines a shape with adimension “D2”, such that the dimension “D1” of the tubular channel isless than the dimension “D2” of the in-vivo introducible antenna.

The flexible loop may be composed of a shape memory alloy configured toautomatically return to an initial shape in the absence of externalforces.

The flexible loop may be sizably adjustable such that the flexible loopcan be reshaped to conform to its surroundings.

The initial shape of the flexible loop may be a circle.

The flexible loop may be configured to be folded backwards to restalongside the semi-rigid elongated member while being inserted into thesurgical site within the patient's body.

The flexible loop may be configured to be folded along the longitudinalaxis of the semi-rigid elongated member to form a crescent-shapedprofile while being withdrawn from the surgical site within thepatient's body.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, identical reference numbers identify similar elementsor acts. The sizes and relative positions of elements in the drawingsare not necessarily drawn to scale. For example, the shapes of variouselements and angles are not drawn to scale, and some of these elementsare arbitrarily enlarged and positioned to improve drawing legibility.Further, the particular shapes of the elements as drawn, are notintended to convey any information regarding the actual shape of theparticular elements, and have been solely selected for ease ofrecognition in the drawings.

Various aspects of the presently disclosed in-vivo introducibleantennae, RF tags, and articles containing them are described hereinbelow with reference to the drawings, wherein:

FIG. 1 is a schematic diagram showing a surgical environmentillustrating a medical provider using an interrogation and detectionsystem to detect an object within a patient that is tagged with an RFIDtag according to one illustrated aspect;

FIG. 2 is a schematic illustration of an in-vivo introducible antennafor detection of surgical implements within a patient's body in activeuse within a surgical site;

FIG. 3A is an enlarged perspective view of an in-vivo introducibleantenna, in a compressed state, being pushed through a channel toward asurgical site within the patient's body;

FIG. 3B is an enlarged perspective view of the in-vivo introducibleantenna, in an expanded state, after being pushed through the channel ofFIG. 3A and emerging into the surgical site within the patient's body;

FIG. 3C is an enlarged perspective view of an in-vivo introducibleantenna being withdrawn from a surgical site within the patient's body;

FIG. 3D is an enlarged perspective view of an in-vivo introducibleantenna, in a folded state while being withdrawn from a surgical sitewithin the patient's body;

FIG. 3E is an enlarged perspective view of an in-vivo introducibleantenna folded backwards while being pushed through a channel toward thesurgical site within the patient's body;

FIG. 3F is an enlarged perspective view of the in-vivo introducibleantenna in a partially unfolded and expanded state, after being pushedthrough the channel of FIG. 3E and emerging into a surgical site withinthe patient's body;

FIG. 4A is a frontal view of an elongated tubular channel and aperturethereof of the trocar-cannula assembly shown in FIG. 2 ;

FIG. 4B is a profile view of the in-vivo introducible antenna of FIGS.1-3F in its initial expanded state as shown in FIG. 3B;

FIG. 4C is a profile view of the in-vivo introducible antenna compressedto form an elongated oval shape under the influence of the elongatedtubular channel, as shown in FIG. 3A; and

FIG. 4D is a profile view of the in-vivo introducible antenna folded toform a crescent shape under the influence of the elongated tubularchannel, as shown in FIG. 3D.

DETAILED DESCRIPTION

In the following description, certain specific details are set forth inorder to provide a thorough understanding of disclosed aspects. However,one skilled in the relevant art will recognize that aspects may bepracticed without one or more of these specific details, or with othermethods, components, materials, etc. In other instances, well-knownstructures associated with transmitters, receivers, or transceivers havenot been shown or described in detail to avoid unnecessarily obscuringdescriptions of the aspects.

Reference throughout this specification to “one aspect” or “an aspect”means that a particular feature, structure or characteristic describedin connection with the aspect is included in at least one aspect. Thus,the appearances of the phrases “in one aspect” or “in an aspect” invarious places throughout this specification are not necessarily allreferring to the same aspect. Furthermore, the particular features,structures, or characteristics may be combined in any suitable manner inone or more aspects.

FIG. 1 depicts a surgical environment “E” in which a medical provider 12operates an interrogation and detection system 10 for detection of RFIDtags to ascertain the presence or absence of objects 100 a in a patient18. The interrogation and detection system 10 may include a signalgenerator 200, and an antenna 300 coupled to the signal generator 200 byone or more communication paths, for example coaxial cable 250. In oneaspect of the interrogation and detection system 10, the antenna 300 maytake the form of a hand-held wand 300 a.

The object 100 a may take a variety of forms, for example instruments,accessories and/or disposable objects useful in performing surgicalprocedures. For instance, the object 100 a may take the form ofscalpels, scissors, forceps, hemostats, and/or clamps. Also for example,the objects 100 a may take the form of surgical sponges, gauze and/orpadding. The object 100 a is tagged, carrying, attached or otherwisecoupled to an RFID tag 100. Aspects of the interrogation and detectionsystem 10 disclosed herein are particularly suited to operate with oneor more RFID tags 100 which are not accurately tuned to a chosen orselected resonant frequency. Consequently, the RFID tags 100 do notrequire high manufacturing tolerances or expensive materials, and thusmay be inexpensive to manufacture.

In use, the medical provider 12 may position the wand 300 a approximatethe patient 18 in order to detect the presence or absence of the one ormore RFID tags 100 and hence an object 100 a. The medical provider 12may in some aspects move the wand 300 a along and/or across the body ofthe patient 18. For a detailed description of an exemplary interrogationand detection system, reference may be made to commonly owned U.S.Patent Application Publication No. 2004/0250819 to Blair et al., titled“Apparatus and Method For Detecting Objects Using Tags And WidebandDetection Device,” filed Mar. 29, 2004, the entire contents of which ishereby incorporated by reference herein.

Referring now to FIG. 2 , interrogation and detection system 10, fordetection of surgical implements 100 a within a patient's body, includesa signal generator 200 to provide an energizing signal for one or moreRFID tags 100 (FIG. 1 ) affixed to an object 100 a (FIG. 1 ). Each RFIDtag is configured to transmit a return signal when energized, such thatan antenna 300 can detect the return signal and confirm the presence ofobjects 100 a within the body of patient 18. The antenna 300 is operablycoupled to the signal generator 200 via a communication cable 250. Wherethe communication cable 250 may be of variable length to provide greaterrange of motion to the clinician handling the antenna 300.

In one aspect of interrogation and detection system 10, the antenna 300is an in-vivo introducible antenna 300 includes a semi-rigid elongatedmember 310 supporting a flexible loop 320 configured to be inserted intosurgical site 15 within the body of patient 18. Accordingly,interrogation and detection system 10 further includes a trocar-cannulaassembly or port 400 to provide an access point for in-vivo introducibleantenna 300 to be inserted into the body of patient 18. At a minimum,with reference to FIG. 2 trocar-cannula assembly 400 provides anelongated tubular channel 410 configured to facilitate the passage ofin-vivo introducible antenna 300 therethrough. Further, a distal end ofelongated tubular channel 410 must provide an open aperture 420 to grantthe in-vivo introducible antenna 300 access to the surgical site 15within the body of patient 18.

With additional reference to FIGS. 3A-F, in-vivo introducible antenna300, as noted above, includes a semi-rigid elongated member 310supporting a flexible loop 320 and must be inserted into a surgical site15 within the body of patient 18. When free from the influence ofexternal forces, flexible loop 320 occupies a region of space too largeto be inserted through elongated tubular channel 410 or aperture 420 oftrocar-cannula assembly 400, see FIGS. 4A and 4B. The increased size offlexible loop 320 is necessary to provide in-vivo introducible antenna300 with a greater range of detection for return signals from RFIDtagged objects within surgical site 15.

In order to be inserted through elongated tubular channel 410 andaperture 420 of trocar-cannula assembly 400 without sacrificing thebenefits of having increased size, flexible loop 320 of in-vivointroducible antenna 300 is composed of a shape memory alloy that ismalleable enough to be compressed, folded, or otherwise reshaped toconform to its surroundings, while also being configured toautomatically return to its original form when free from the influenceof external forces. More specifically, the in-vivo introducible antenna300 may be made from materials such as, nitinol, spring steel, silver,gold, copper, and various alloys of each listed material. In FIG. 3A,flexible loop 320 is initially circular in shape, but is compressedinward to form an elongated oval shape while being translated distallyin direction “A1” through elongated tubular channel 410 toward thesurgical site. Upon emerging through aperture 420 of elongated tubularchannel 410 and entering the surgical site, flexible loop 320automatically returns to its initial circular shape when free from theexternal influence of elongated tubular channel 410, as shown in FIG.3B. Note, in other aspects the initial shape of flexible loop 320 may benon-circular, for example tear drop-shaped or oval.

In some aspects, flexible loop 320 can be folded along a longitudinalaxis of semi-rigid elongated member 310 to form a crescent shape whilebeing translated proximally in direction “A2” through elongated tubularchannel 410 away from the surgical site as shown in FIGS. 3C and 3D. Instill other aspects, the flexible loop 320 can be folded backward torest alongside the semi-rigid elongated member 310 in addition to beingcompressed inward to form an elongated oval shape while being translateddistally in direction “A1” through the tubular channel 410, only toautomatically unfold and return to its original circular shape when freefrom the external influence of elongated tubular channel 410 uponemerging through aperture 420 and entering the surgical site, as shownin FIGS. 3E and 3F.

Now referring to FIGS. 4A-D, as noted above, in-vivo introducibleantenna 300 occupies a region of space too large to be inserted throughelongated tubular channel 410 or aperture 420 of trocar-cannula assembly400 when free from the influence of external forces.

FIG. 4A shows a frontal view of tubular channel 410, emphasizing thattubular channel 410 defines a generally circular shape having dimensionor diameter “D1”. Similarly, FIG. 4B shows a top view of in-vivointroducible antenna 300, wherein the flexible loop 320 defines agenerally circular shape having dimension or diameter “D2” when measuredtransversely relative to longitudinal axis “X”. Longitudinal axis “X”runs parallel to the direction of movement of in-vivo introducibleantenna 300 within tubular channel 410, and therefore transversemeasurement of dimension “D2” of flexible loop 32 presents a moreaccurate basis for comparing the relative sizes of tubular channel 410and flexible loop 320. From FIGS. 4A and 4B, the dimensions “D1”, “D2”of tubular channel 410 and flexible loop 320 show that “D2” is greaterthan “D1”. Correspondingly, any measurement of size calculated based ondimensions “D1”, “D2” will always show that flexible loop 320 is largerin size than tubular channel 410, thereby emphasizing the need forin-vivo introducible antenna 300 to be sizably adjustable in order topass through elongated channel 410 and emerge out of aperture 420. FIG.4C shows the elongated oval shape of flexible loop 320 due tocompression forces exerted by the inner surface of elongated tubularchannel 410 while being distally translated in direction, “A1” as shownin FIG. 3A. Similarly, FIG. 4D shows the crescent shape of flexible loop320 as a result of being folded along longitudinal axis “X” ofsemi-rigid elongated member 310 while being proximally translated indirection “A2” through elongated tubular channel 410, as shown in FIG.3D.

While aspects of the disclosure have been shown in the drawings, it isnot intended that the disclosure be limited thereto, as it is intendedthat the disclosure be as broad in scope as the art will allow and thatthe specification be read likewise. Therefore, the above descriptionshould not be construed as limiting, but merely as exemplifications ofparticular aspects. Those skilled in the art will envision othermodifications within the scope and spirit of the claims appended hereto.

1-20. (canceled)
 21. An interrogation and detection system for detectionof surgical implements within a patient's body, comprising: one or moreRFID tags configured to transmit one or more return signals whenenergized, each RFID tag affixed to a surgical implement within thepatient's body; a remote signal generator configured to generate anenergizing signal for the one or more RFID tags; and an in-vivointroducible antenna operably coupled to the signal generator, thein-vivo introducible antenna including: a semi-rigid elongated memberhaving a proximal end connected to the remote signal generator, and adistal end; and a flexible loop supported at the distal end of thesemi-rigid elongated member and connected to the remote signalgenerator, wherein the flexible loop is configurable between an expandedstate for receiving the one or more return signals transmitted by theone or more RFID tags, and a collapsed state, smaller than the expandedstate, for insertion into the patient's body, wherein the flexible loopis distally oriented in relation to the semi-rigid elongated member. 22.The system of claim 21, further comprising: a trocar-cannula assemblyincluding a tubular channel configured to facilitate passage of thein-vivo introducible antenna therethrough and into the patient's body,wherein the tubular channel defines a shape having a first dimension;wherein the flexible loop of the in-vivo introducible antenna defines ashape having a second dimension when in the expanded state; and whereinthe first dimension of the tubular channel is less than the seconddimension of the flexible loop of the in-vivo introducible antenna. 23.The system of claim 22, wherein the flexible loop of the in-vivo antennais composed of a shape memory alloy configured to automatically returnto an initial shape in the absence of external forces.
 24. The system ofclaim 23, wherein the flexible loop of the in-vivo antenna is circularwhen in the expanded state.
 25. The system of claim 24, wherein theflexible loop is configured to be formed into an elongated oval shape,when in a collapsed state, so as to have a transverse dimension that isless than the first dimension of the tubular channel for translationthrough the tubular channel.
 26. The system of claim 24, wherein theflexible loop is configured to be folded along an axis of the semi-rigidelongated member to form a crescent-shaped profile while beingtranslated through the tubular channel.
 27. The system of claim 24,wherein the flexible loop is tear drop-shaped.
 28. The system of claim22, wherein the flexible loop is larger in size than the tubular channelwhen in the expanded state.
 29. A method for detecting one or moresurgical implements within a patient's body, comprising: pushing anin-vivo introducible antenna distally through a channel having a firstdimension defined within a trocar-cannula assembly and into a surgicalsite within the patient's body, wherein the trocar-cannula assemblyincludes a tubular channel, wherein the in-vivo introducible antennaincludes a semi-rigid elongated member having a proximal end connectedto a remote signal generator, and a distal end, and a flexible loopsupported at the distal end of the semi-rigid elongated member and beingconnected to the remote signal generator, wherein the flexible loop isconfigurable between an expanded state for receiving one or more returnsignals transmitted by one or more RFID tags, and a collapsed state,smaller than the expanded state, for insertion into the patient's body,wherein the flexible loop is distally oriented in relation to thesemi-rigid elongated member; generating an energizing signal configuredto stimulate one or more RFID tags into transmitting a return signal;transmitting the energizing signal directly into the surgical sitewithin the patient's body through an expanded portion of the in-vivointroducible antenna; scanning for any return signals from one or moreRFID tags affixed to each surgical implement placed within the patient'sbody before a commencement of surgery; and alerting a clinician to apresence of the one or more RFID tags affixed to each surgical implementupon detection of the one or more return signals.
 30. The method ofclaim 29, where the flexible loop is a portion of the in-vivointroducible antenna configured to automatically unfold to occupy anexpanded area.
 31. The method of claim 30, further including: pullingthe unfolded flexible loop of the in-vivo introducible antennaproximally through an aperture and channel of the trocar-cannulaassembly such that the unfolded flexible loop is compressed by thechannel.
 32. The method of claim 31, wherein the compression of theflexible loop facilitates complete withdrawal of the in-vivointroducible antenna from the trocar-cannula assembly.
 33. The method ofclaim 32, wherein the flexible loop is circular in shape and is furtherconfigured to fold along an axis of the semi-rigid elongated member toform a crescent-shaped profile while being pulled proximally through thechannel of the trocar-cannula assembly.
 34. The method of claim 29,wherein the flexible loop is configured to be formed into an elongatedoval shape, when in a collapsed state, so as to have a transversedimension that is less than the first dimension of the tubular channelfor translation through the tubular channel.
 35. A resizable in-vivointroducible antenna for insertion into a surgical site and detection ofRFID tagged surgical implements within a patient's body, comprising: asemi-rigid elongated member having a proximal end connected to a remotesignal generator, and a distal end; and a flexible loop supported at thedistal end of the semi-rigid elongated member and connected to theremote signal generator, wherein the flexible loop is configurablebetween an expanded state for receiving one or more return signalstransmitted by the one or more RFID tags, and a collapsed state, smallerthan the expanded state, for insertion into the patient's body, whereinthe flexible loop is distally oriented in relation to the semi-rigidelongated member.
 36. The antenna of claim 35, wherein the flexible loopis composed of a shape memory alloy configured to automatically returnto an initial shape in the absence of external forces.
 37. The antennaof claim 36, wherein the flexible loop is sizably adjustable such thatthe flexible loop can be reshaped to conform to its surroundings. 38.The antenna of claim 37, wherein the initial shape of the flexible loopis a circle.
 39. The antenna of claim 37, wherein the flexible loop isconfigured to be inserted into the surgical site within the patient'sbody before the rigid elongated member.
 40. The antenna of claim 37,wherein the flexible loop is configured to be folded along an axis ofthe semi-rigid elongated member to form a crescent-shaped profile whilebeing translated proximally through a tubular channel of atrocar-cannula assembly.